I started with almost no experience and took me about 2.5 months (120-150 hours) of preparation for the OCAJP7 - Java SE 7 Programmer I - 1Z0-803 exam. I used the book from Mala Gupta “OCA_Java_SE_7_Programmer I exam” and passed the real exam with 86%.
After this it took me about 11.5 months (550-600 hours) of preparation for the OCPJP7 - Java SE 7 Programmer II - 1Z0-804 exam. I used the Enthuware Software, Oracle Online Tutorial and a couple of other websites, Java Online API and the book from Sierra and Bates “OCP Java SE 7 Programmer Study Guide”. I passed the exam yesterday with 70%.
It was a hard period of time, but now I’m very happy and proud!